Influence of manganiferous fragments on the trace element geochemistry of pelagic sediments, North-West Indian Ocean

Abstract

Trace element analyses of eight carbonate sediment cores from a limited area on the flanks of the Carlsberg Ridge in the North-west Indian Ocean indicate that upward migration of manganese is not a significant process in this pelagic environment. Element migration is not therefore considered to be an important factor in controlling the trace element geochemistry of manganese nodules from this area. The erratic distribution of manganese within the sediment column is attributed to the random inclusion within the sediment of manganese-rich fragments originating from the disintegration of manganese encrustations on the sea Hoor and the subsequent dispersal of these fragments by bottom current activity. There is no evidence for the in situ formation of manganese micronodules within the sediment column in this locality.